Geothermal energy developers plan to pump 24 million gallons of water into the side of a dormant volcano in Central Oregon this summer to demonstrate new technology they hope will give a boost to a green energy sector that has yet to live up to its promise.

They hope the water comes back to the surface fast enough and hot enough to create cheap, clean electricity that isn’t dependent on sunny skies or stiff breezes — without shaking the earth and rattling the nerves of nearby residents.

Renewable energy has been held back by cheap natural gas, weak demand for power and waning political concern over global warming. Efforts to use the earth’s heat to generate power, known as geothermal energy, have been further hampered by technical problems and worries that tapping it can cause earthquakes.

Even so, the federal government, Google and other investors are interested enough to bet $43 million on the Oregon project. They are helping AltaRock Energy, Inc. of Seattle and Davenport Newberry Holdings LLC of Stamford, Conn., demonstrate whether the next level in geothermal power development can work on the flanks of Newberrry Volcano, located about 20 miles south of Bend, Ore.

“We know the heat is there,’’ said Susan Petty, president of AltaRock. “The big issue is can we circulate enough water through the system to make it economic.’’

DELAYED geothermal projects could make it across the line this year as two SA-focused companies move further toward producing power, the industry association says. Geothermal company Geodynamics plans to drill its Habanero-4 well in the first financial quarter, taking it toward producing power to Innamincka.

Australian Geothermal Energy Association chief executive Susan Jeanes said "this is the year the industry can prove itself"'. She said the Geodynamics project, that suffered a major setback with a well blowout at Habanero 3 well in 2009, would also work toward fracturing rocks to achieve circulation of super hot water for its 1MW plant.

SA geothermal company Petratherm has drilled a deep well at its Paralana project north of the Flinders Ranges and completed a successful fracture. ...

Ms Jeanes was upbeat about the industry saying if the drilling work was successful this year it could help lead the whole sector forward. "We expect, that given (Geodynamics) successfully proved the concept with Habanero one and three that they will be successful with Habanero one and four because they are drilling into the same geological structure," she said. "That success at Innamincka will provide a huge boost of confidence in the sector, then the sector hopes that will be followed by a successful well at Paralana."

Petratherm managing director Terry Kallis said plans to begin drilling on a second deep well in the Paralana project were still on track for later this year despite TRUenergy's exit. "We haven't changed our plans. we're still on track to look to drill later this year," Mr Kallis said.